We have developed a series of attenuated viral vaccine vectors, based on murin Mengovirus, and adapted these vectors to carry large sequences from heterologous proteins. We need to know how efficiently the heterologous proteins are expressed during HeLa cell infection. We intend to infect cells on microscope slides, fix them, then stain them with fluorescent antibodies that can be detected (and recorded) by confocal microscopy. Alternatively, the heterologous protein itself (GFP), might be detected under the scope, using the appropriate wavelength or filters.